Framework for EVPN Designated Forwarder Election Extensibility
draft-ietf-bess-evpn-df-election-framework-09
BESS Workgroup J. Rabadan, Ed.
Internet Draft Nokia
Updates: 7432 S. Mohanty, Ed.
Intended status: Standards Track A. Sajassi
Cisco
J. Drake
Juniper
K. Nagaraj
S. Sathappan
Nokia
Expires: July 28, 2019 January 24, 2019
Framework for EVPN Designated Forwarder Election Extensibility
draft-ietf-bess-evpn-df-election-framework-09
Abstract
An alternative to the Default Designated Forwarder (DF) selection
algorithm in Ethernet VPN (EVPN) networks is defined. The DF is the
Provider Edge (PE) router responsible for sending broadcast, unknown
unicast and multicast (BUM) traffic to multi-homed Customer Equipment
(CE) on a particular Ethernet Segment (ES) within a VLAN. In
addition, the capability to influence the DF election result for a
VLAN based on the state of the associated Attachment Circuit (AC) is
specified. This document clarifies the DF Election Finite State
Machine in EVPN, therefore it updates the EVPN specification.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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time. It is inappropriate to use Internet-Drafts as reference
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Default Designated Forwarder (DF) Election in EVPN . . . . 3
1.2. Problem Statement . . . . . . . . . . . . . . . . . . . . . 6
1.2.1. Unfair Load-Balancing and Service Disruption . . . . . 6
1.2.2. Traffic Black-Holing on Individual AC Failures . . . . 7
1.3. The Need for Extending the Default DF Election in EVPN . . 10
2. Conventions and Terminology . . . . . . . . . . . . . . . . . . 11
3. Designated Forwarder Election Protocol and BGP Extensions . . . 12
3.1. The DF Election Finite State Machine (FSM) . . . . . . . . 12
3.2. The DF Election Extended Community . . . . . . . . . . . . 15
3.2.1. Backward Compatibility . . . . . . . . . . . . . . . . 18
3.3. Auto-Derivation of ES-Import Route Target . . . . . . . . . 18
4. The Highest Random Weight DF Election Algorithm . . . . . . . . 18
4.1. HRW and Consistent Hashing . . . . . . . . . . . . . . . . 19
4.2. HRW Algorithm for EVPN DF Election . . . . . . . . . . . . 19
5. The Attachment Circuit Influenced DF Election Capability . . . 21
5.1. AC-Influenced DF Election Capability For VLAN-Aware
Bundle Services . . . . . . . . . . . . . . . . . . . . . . 23
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6. Solution Benefits . . . . . . . . . . . . . . . . . . . . . . . 24
7. Security Considerations . . . . . . . . . . . . . . . . . . . . 25
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